LTC3858-1

PRODUCTION

LTC3858-1

Low I_Q, Dual 2-Phase Synchronous Step-Down Controller

PRODUCTION

High Efﬁciency Dual 8.5V/3.3V Step-Down Converter slide

Efﬁciency and Power Loss vs Load Current slide

High Efﬁciency Dual 8.5V/3.3V Step-Down Converter

Efﬁciency and Power Loss vs Load Current

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Part Models 8

1ku List Price Starting From $4.63

Features

Low Operating I_Q: 170μA (One Channel On)
Wide Output Voltage Range: 0.8V ≤ V_OUT ≤ 24V
Wide V_IN Range: 4V to 38V
R_SENSE or DCR Current Sensing
Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
OPTI-LOOP^® Compensation Minimizes C_OUT
Phase-Lockable Frequency (75kHz-850kHz)
Programmable Fixed Frequency (50kHz-900kHz)
Selectable Continuous, Pulse-Skipping or Burst Mode^® Operation at Light Loads
Very Low Dropout Operation: 99% Duty Cycle
Adjustable Output Voltage Soft-Start
Power Good Output Voltage Monitor
Output Overvoltage Protection
Output Latch-Off Protection During Short Circuit
Low Shutdown I_Q: 8μA
Internal LDO Powers Gate Drive from V_IN or EXTV_CC
No Current Foldback During Start-Up
Tiny 4mm × 5mm QFN and Narrow SSOP Packages

Additional Details

The LTC3858-1 is a high performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. Power loss and noise due to the input capacitor ESR are minimized by operating the two controller outputs out of phase.

The 170μA no-load quiescent current extends operating life in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3858-1 features a precision 0.8V reference and a power good output indicator. A wide 4V to 38V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries.

Independent soft-start pins for each controller ramp the output voltages during start-up. The output latch-off feature protects the circuit in short-circuit conditions.

For a leadless 32-pin QFN package with the additional features of adjustable current limit, clock out, phase modulation and two PGOOD outputs, see the LTC3858 data sheet.


	LTC3858	LTC3858-1	LTC3858-2
Features	Adjustable Current Limit, Clock Output, Phase Modulation, 2 PGOOD Outputs	Fixed Current Limit, One PGOOD Output	Overvoltage protection crowbar and short-circuit latchoff disabled
Package	QFN-32	SSOP-28	QFN-32

Applications

Automotive Systems
Battery Operated Digital Devices
Distributed DC Power Systems

View All Documentation

Ask a Question

Submit your question below and we will return the best answer from ADI’s knowledge database:

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Support

Analog Devices Support Portal is a one-stop shop to answer all your ADI questions.

Visit the ADI Support Page

Ask the ADI community for help.

Ask the EngineerZone Community

FAQs

Sales & Ordering FAQs

Part Models 8

1ku List Price Starting From $4.63

Technical Documents 3

LTC3858-1: Low I_Q, Dual 2-Phase Synchronous Step-Down Controller Data Sheet 12/02/2010

R526 Reliability Data 03/26/2018

DC1352A - Demo Board 10/22/2009

Design Resources 8

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LTC3858EGN-1#PBF	28-Lead SSOP (Narrow 0.15 Inch)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858EGN-1#TRPBF	28-Lead SSOP (Narrow 0.15 Inch)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858EUFD-1#PBF	28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858EUFD-1#TRPBF	28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858IGN-1#PBF	28-Lead SSOP (Narrow 0.15 Inch)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858IGN-1#TRPBF	28-Lead SSOP (Narrow 0.15 Inch)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858IUFD-1#PBF	28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3858IUFD-1#TRPBF	28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys

LTC3858EGN-1#PBF
Pin/Package Drawing
28-Lead SSOP (Narrow 0.15 Inch)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858EGN-1#TRPBF
Pin/Package Drawing
28-Lead SSOP (Narrow 0.15 Inch)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858EUFD-1#PBF
Pin/Package Drawing
28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858EUFD-1#TRPBF
Pin/Package Drawing
28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858IGN-1#PBF
Pin/Package Drawing
28-Lead SSOP (Narrow 0.15 Inch)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858IGN-1#TRPBF
Pin/Package Drawing
28-Lead SSOP (Narrow 0.15 Inch)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858IUFD-1#PBF
Pin/Package Drawing
28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3858IUFD-1#TRPBF
Pin/Package Drawing
28-Lead QFN (4mm x 5mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

PCN/PDN Information

Filter by Model

Part Models

Product Lifecycle

PCN

Oct 3, 2024

- 24_0235

(QSOP/SSOP PKG) Migrating Bottom Trace Code Marking to Top Side Laser Marking

LTC3858EGN-1#PBF

PRODUCTION

LTC3858EGN-1#TRPBF

PRODUCTION

LTC3858IGN-1#PBF

PRODUCTION

LTC3858IGN-1#TRPBF

PRODUCTION

pdf

PCN24_0235_Form

xls

Material_Report

pdf

Other

xlsm

Delta Qualification Matrix

Aug 10, 2022

- 22_0177

Laser Top Mark Conversion for QSOP20_24_28 Assembled in ADPG [PNG] and UTL

LTC3858EGN-1#PBF

PRODUCTION

LTC3858EGN-1#TRPBF

PRODUCTION

LTC3858IGN-1#PBF

PRODUCTION

LTC3858IGN-1#TRPBF

PRODUCTION

pdf

PCN22_0177_Form

xls

Material_Report

xlsm

Delta Qualification Matrix

Jul 31, 2020

- 20_0245

Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan)

LTC3858EGN-1#PBF

PRODUCTION

LTC3858EGN-1#TRPBF

PRODUCTION

LTC3858EUFD-1#PBF

PRODUCTION

LTC3858EUFD-1#TRPBF

PRODUCTION

LTC3858IGN-1#PBF

PRODUCTION

LTC3858IGN-1#TRPBF

PRODUCTION

LTC3858IUFD-1#PBF

PRODUCTION

LTC3858IUFD-1#TRPBF

PRODUCTION

pdf

PCN20_0245_Form

xls

Material_Report

xlsm

Delta Qualification Matrix

pdf

Other

pdf

Qualification Results Summary

Jan 20, 2022

- 21_0269

Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products

LTC3858EUFD-1#PBF

PRODUCTION

LTC3858EUFD-1#TRPBF

PRODUCTION

LTC3858IUFD-1#PBF

PRODUCTION

LTC3858IUFD-1#TRPBF

PRODUCTION

pdf

PCN21_0269_Form

xls

Material_Report

pdf

Detailed Change Description

pdf

Qualification Results Summary

Filter by Model

Part Models

Product Lifecycle

PCN

Oct 3, 2024

- 24_0235

(QSOP/SSOP PKG) Migrating Bottom Trace Code Marking to Top Side Laser Marking

LTC3858EGN-1#PBF

PRODUCTION

LTC3858EGN-1#TRPBF

PRODUCTION

LTC3858IGN-1#PBF

PRODUCTION

LTC3858IGN-1#TRPBF

PRODUCTION

pdf

PCN24_0235_Form

xls

Material_Report

pdf

Other

xlsm

Delta Qualification Matrix

Aug 10, 2022

- 22_0177

Laser Top Mark Conversion for QSOP20_24_28 Assembled in ADPG [PNG] and UTL

LTC3858EGN-1#PBF

PRODUCTION

LTC3858EGN-1#TRPBF

PRODUCTION

LTC3858IGN-1#PBF

PRODUCTION

LTC3858IGN-1#TRPBF

PRODUCTION

pdf

PCN22_0177_Form

xls

Material_Report

xlsm

Delta Qualification Matrix

Jul 31, 2020

- 20_0245

Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan)

LTC3858EGN-1#PBF

PRODUCTION

LTC3858EGN-1#TRPBF

PRODUCTION

LTC3858EUFD-1#PBF

PRODUCTION

LTC3858EUFD-1#TRPBF

PRODUCTION

LTC3858IGN-1#PBF

PRODUCTION

LTC3858IGN-1#TRPBF

PRODUCTION

LTC3858IUFD-1#PBF

PRODUCTION

LTC3858IUFD-1#TRPBF

PRODUCTION

pdf

PCN20_0245_Form

xls

Material_Report

xlsm

Delta Qualification Matrix

pdf

Other

pdf

Qualification Results Summary

Jan 20, 2022

- 21_0269

Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products

LTC3858EUFD-1#PBF

PRODUCTION

LTC3858EUFD-1#TRPBF

PRODUCTION

LTC3858IUFD-1#PBF

PRODUCTION

LTC3858IUFD-1#TRPBF

PRODUCTION

pdf

PCN21_0269_Form

xls

Material_Report

pdf

Detailed Change Description

pdf

Qualification Results Summary

Companion Parts 4

Parts	Product Life Cycle	Description
Dual-Supply Monitors1
LTC2960	RECOMMENDED FOR NEW DESIGNS	36V Nano-Current Two-Input Voltage Monitor
Multiple Output Buck Regulators1
LTC3880	RECOMMENDED FOR NEW DESIGNS	Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management
Pushbutton Controllers1
LTC2955	RECOMMENDED FOR NEW DESIGNS	Pushbutton On/Off Controller with Automatic Turn-On
Surge Stopper, Overvoltage, and Overcurrent Protection1
LT4363	RECOMMENDED FOR NEW DESIGNS	High Voltage Surge Stopper with Current Limit

DC1352A-B

LTC3858EGN-1 Demo Board | Dual Output, 2-Phase, 4.5V ≤ VIN ≤ 36V, VOUT1 = 3.3V @ 5A, VOUT2 = 8.5V @ 3A

DC1352A-B

LTC3858EGN-1 Demo Board | Dual Output, 2-Phase, 4.5V ≤ VIN ≤ 36V, VOUT1 = 3.3V @ 5A, VOUT2 = 8.5V @ 3A

Buy Now View Details

Product Detail

Demonstration circuit 1352A is a low quiescent current, dual output 2-phase, synchronous buck converter demo board featuring the LTC3857EGN-1 or LTC3858EGN-1. It features a 4.5V to 36V input voltage range and provides 3.3V / 5A and 8.5V / 3A outputs. Two versions of the board are available. The DC-1352A-A is for the LTC3857EGN-1, which offers lower quiescent current and smaller burst mode ripple, while the DC1352A-B is for the LTC3858EGN-1 which offers latch-off protection and increased burst mode efficiency.

Resources

PDF

DC1352A - Schematic

89.00K

PDF

DC1352A - Demo Board

1.00M

ZIP

DC1352A - Design Files

3.00M

DC1352A-B

LTC3858EGN-1 Demo Board | Dual Output, 2-Phase, 4.5V ≤ VIN ≤ 36V, VOUT1 = 3.3V @ 5A, VOUT2 = 8.5V @ 3A

LTspice 1

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

Lt Spice

LTC3858-1 Demo Circuit - Dual Synchronous Step Down (4.5-36V to 3.3V @ 5A & 8.5V @ 3A)

6.00K

LTpowerCAD 1

LTpowerCAD^® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.

To open the project file for this circuit:

Step 1: Download and install LTpowerCAD on your computer.

Step 2: Click on the link(s) in the section below to download part-specific project files.

Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.

LTpowerCAD download and documentation